1. Field of the Invention
This invention relates to a release technique and to devices which may be quickly released by this technique.
2. Description of the Prior Art
Various quick release devices are known in the art. Among these are devices in which mechanical release or separation is accomplished by means of an explosive charge. Such devices and references showing the same include, for example, explosive both (Menichelli U.S. Pat. No. 3,374,702), cable and line cutters (Brizzolara U.S. Pat. Nos. 3,452,631 and 3,482,484) piston actuators (McGirr U.S. Pat. No. 3,354,634), and explosively actuated valves. Other prior art devices are actuated by means of a high explosive in the form of a detonating card or a sheet explosive.
Other prior art explosively actuated devices include the following:
ICI United States Inc. data sheet entitled "Frangible Link--Installation--Replacement" shows a frangible link which is weakened at its mid-portion by notches, and an electrically initiated radially expandable explosive actuator which ruptures the link on command.
Applicant's U.S. Pat. No. 3,897,799 shows a quick opening sleeve valve in which frangible sealing rings formed by brazing or welding secure a slidable sleeve to a stationary shell. Ignition of a squib causes the sleeve to slide and breaks the sealing rings, opening the valve.
U.S. Pat. No. 3,774,807 to Keathley and Lee (the applicant herein) shows an explosively actuated piston valve. In FIGS. 4 and 5, a slidable valve element is secured to a casing member by solder prior to actuation.
U.S. Pat. No. 4,106,875 to Jewett shows an explosively actuated tongue and groove joint which includes an explosive cord between the tongue end wall and the base of the groove, and extending the full length of the joint. The joint is held together by bolts. Firing of the explosive cord causes the forward end of the tongue to collapse, opening the bolt holes. The force of the explosion also drives the two halves of the joint apart.
U.S. Pat. No. 3,660,794 to Brizzolara shows a link comprising two link members that are held together by a fusible ring which is melted on command by burning of a combustible composition.
Devices having releasable joints that are broken by means other than explosives are also known in the art. For example, an automatic sprinkler which is normally held closed by an arrangement that includes a fusible link is shown in Fire Protection Handbook 15th edition, 1981, pages 17-32 to 17-35 and especially FIG. 17-36 on page 17-33 thereof. When a predetermined temperature is reached, the solder joining the link parts together melts, permitting the link parts to separate and allowing the automatic sprinkler to open.